DOCSLIB.ORG

Apomixis Is Not Prevalent in Subnival to Nival Plants of the European Alps

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Apomixis Is Not Prevalent in Subnival to Nival Plants of the European Alps Annals of Botany 108: 381–390, 2011 doi:10.1093/aob/mcr142, available online at www.aob.oxfordjournals.org Apomixis is not prevalent in subnival to nival plants of the European Alps Elvira Ho¨randl1,*, Christoph Dobesˇ2, Jan Suda3,4, Petr Vı´t3,4, Toma´sˇ Urfus3,4, Eva M. Temsch1, Anne-Caroline Cosendai1, Johanna Wagner5 and Ursula Ladinig5 1Department of Systematic and Evolutionary Botany, Faculty of Life Sciences, University of Vienna, A-1030 Vienna, Austria, 2Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, A-1090 Vienna, Austria, 3Department of Botany, Faculty of Science, Charles University in Prague, CZ-128 01 Prague, Czech Republic, 4Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Pru˚honice, Czech Republic and 5Institute of Botany, University of Innsbruck, A-6020 Innsbruck, Austria * For correspondence. E-mail [email protected] Received: 2 December 2010 Returned for revision: 14 January 2011 Accepted: 28 April 2011 Published electronically: 1 July 2011 † Background and Aims High alpine environments are characterized by short growing seasons, stochastic climatic conditions and fluctuating pollinator visits. These conditions are rather unfavourable for sexual reproduction of flowering plants. Apomixis, asexual reproduction via seed, provides reproductive assurance without the need of pollinators and potentially accelerates seed development. Therefore, apomixis is expected to provide selective advantages in high-alpine biota. Indeed, apomictic species occur frequently in the subalpine to alpine grassland zone of the European Alps, but the mode of reproduction of the subnival to nival flora was largely unknown. † Methods The mode of reproduction in 14 species belonging to seven families was investigated via flow cyto- metric seed screen. The sampling comprised 12 species typical for nival to subnival plant communities of the European Alps without any previous information on apomixis (Achillea atrata, Androsace alpina, Arabis caerulea, Erigeron uniflorus, Gnaphalium hoppeanum, Leucanthemopsis alpina, Oxyria digyna, Potentilla frigida, Ranunculus alpestris, R. glacialis, R. pygmaeus and Saxifraga bryoides), and two high-alpine species with apomixis reported from other geographical areas (Leontopodium alpinum and Potentilla crantzii). † Key Results Flow cytometric data were clearly interpretable for all 46 population samples, confirming the utility of the method for broad screenings on non-model organisms. Formation of endosperm in all species of Asteraceae was documented. Ratios of endosperm : embryo showed pseudogamous apomixis for Potentilla crantzii (ratio approx. 3), but sexual reproduction for all other species (ratios approx. 1.5). † Conclusions The occurrence of apomixis is not correlated to high altitudes, and cannot be readily explained by selective forces due to environmental conditions. The investigated species have probably other adaptations to high altitudes to maintain reproductive assurance via sexuality. We hypothesize that shifts to apomixis are rather connected to frequencies of polyploidization than to ecological conditions. Key words: Apomixis, European Alps, endosperm, flow cytometric seed screen, high-altitude plants, polyploidy, sexual reproduction. INTRODUCTION systems, flowering plants colonizing higher altitudes have to cope with conditions that are rather unfavourable for sexual Alpine biota often have a tendency to apomixis, the mode of reproduction. Colder climates, a short growing season and reproduction via asexually formed seed (Asker and Jerling, occasional frost during the reproductive period threaten a per- 1992). Apomictic plants show a higher abundance of seed than manent risk of seed loss, especially for plants that need a long their sexual relatives in higher altitudes and latitudes, in pre- time for seed development (e.g. Ladinig and Wagner, 2007; viously glaciated areas and in disturbed habitats Wagner et al., 2011). Apomixis, in contrast, is often associated (Bierzychudek, 1985; Ho¨randl, 2006; Ho¨randl et al., 2008). with an acceleration of developmental pathways via maturation This distribution pattern is most pronounced in cases of gameto- of embryo sacs before anthesis and pollination (e.g. Carman, phytic apomixis which involves the formation of an unreduced 1997; Grimanelli et al., 2001; Carman et al., 2011). Such pre- embryo sac and the development of an unreduced egg cell cocious development, known from alpine species of without fertilization. In contrast, the formation of embryos out Alchemilla (Fro¨hner, 1990) and from Hieracium alpinum of nucellar tissues (adventitious embryony) is more abundant (Skawin´ska, 1963), would allow for rapid seed formation in in tropical plants (Richards, 1997). a short growing season. Unfavourable weather conditions in The relationship of asexual reproduction to certain ecologi- high altitudes can reduce pollinator activities (e.g. Warren cal conditions has often been referred to selective forces by the et al., 1988; McCall and Primack, 1992), which may limit environment (Bell, 1982; Asker and Jerling, 1992). In the seed set for outcrossing plants (e.g. Mun˜oz and Arroyo, European Alps and in other comparable temperate mountain 2006). Therefore, reproductive assurance that is independent # The Author 2011. Published by Oxford University Press on behalf of the Annals of Botany Company. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 382 Ho¨randl et al. — Apomixis is not prevalent in subnival to nival plants of pollinators, as it is provided by apomixis or autogamy, between mountain systems (reviewed by Ho¨randl et al., would be advantageous in alpine habitats. Above the snowline, 2008; Ho¨randl, 2011), which infers that apomixis cannot be abiotic conditions become increasingly extreme in all these predicted for a certain region from studies on accessions in aspects. other mountain systems. Historical factors may have also promoted the occurrence of The reason for this lack of information on high-alpine plants apomixis in the Alps. Glaciations of the Pleistocene have is mostly due to methodological problems: experimental caused range fluctuations of species and may have brought pre- approaches (e.g. bagging and emasculation procedures) are dif- viously isolated species together, thereby increasing frequen- ficult to monitor in the field under high-alpine conditions, and cies of secondary contact hybridization and polyploidization do not discrimate between selfing and pollen-dependent apo- (Hewitt, 1996, 2004). Hybridization and/or polyploidy have mixis (pseudogamy; see Ho¨randl et al., 2008). This is critical been thought to cause the epigenetic and genetic changes because approx. 90 % of apomicts is in fact pseudogamous which would cause shifts to gametophytic apomixis (e.g. (Mogie, 1992). Reproductive tissues for studying embryo-sac Carman, 1997; Grimanelli et al., 2001; Koltunow and development before anthesis (e.g. after Herr, 1971, 1992)are Grossniklaus, 2003; Ho¨randl, 2009a, b). Moreover, uniparental often not accessible in high-alpine plants. In the lowlands, high- reproduction provides the additional advantage of enhanced alpine plants often do not flower in cultivation. Large-scale colonization abilities: a single individual can found a new progeny tests using molecular markers are often hampered by population (Baker’s law: Baker, 1967; Ho¨randl, 2006; low germination rates. For all these reasons, modes of reproduc- Ho¨randl et al., 2008). In the European Alps, the postglacial tion in high-alpine plants have remained largely unknown. retreat of glaciers offered opportunities for colonization by The recently developed method of flow cytometric seed screen apomictic plants (Cosendai and Ho¨randl, 2010). (FCSS; Matzk et al.,2000) can overcome these problems. FCSS The European Alps comprise ecologically distinct altitudi- measures DNA content in mature seeds and can therefore infer nal belts (Ozenda, 1988; Ellenberg and Leuschner, 2010): the DNA ploidy levels of embryo and endosperm, which the forest zone (montane zone) reaches 1300 m/1500 m a.s.l. allows the mode of apomixis to be determined (Krahulcova´ in the north/south, respectively, and is followed by the subal- and Rotreklova´, 2010). Sexual reproduction is characterized by pine zone (upper limits 2000 m/2200 m) with a mosaic of double fertilization, the egg cell and the central cell of the patchy forest, shrub communities and pastures. The alpine embryo sac, and therefore the resulting ratio of embryo (n + n) zone (upper limits 2400 m/2600 m) is characterized by a to endosperm (2n + n) equals to 2 : 3. Gametophytic apomixis cover of vegetation by small shrubs and grassland. This veg- involves the formation of an unreduced embryo sac, and etation in the subnival zone (upper limits 2700/2900 m) the development of the unreduced egg cell without fertili- breaks up into isolated patches and is increasingly replaced zation. Seeds formed via apomixis, in contrast, have therefore by screes, permanent snow fields and rocks. The nival zone 1 : 2, 1 : 2.5 or 1 : 3 ratios of embryo (2n) to endosperm (2n + (from 2700/2900 m up to 4500 m) is characterized by glaciers 2n + 0, 2n + 2n + n or 2n + 2 n + n + n), depending on the and a predominance of cryptogams in patchy remnants of veg- contribution
Load more

Recommended publications
  • "National List of Vascular Plant Species That Occur in Wetlands: 1996 National Summary."
    Intro 1996 National List of Vascular Plant Species That Occur in Wetlands The Fish and Wildlife Service has prepared a National List of Vascular Plant Species That Occur in Wetlands: 1996 National Summary (1996 National List). The 1996 National List is a draft revision of the National List of Plant Species That Occur in Wetlands: 1988 National Summary (Reed 1988) (1988 National List). The 1996 National List is provided to encourage additional public review and comments on the draft regional wetland indicator assignments. The 1996 National List reflects a significant amount of new information that has become available since 1988 on the wetland affinity of vascular plants. This new information has resulted from the extensive use of the 1988 National List in the field by individuals involved in wetland and other resource inventories, wetland identification and delineation, and wetland research. Interim Regional Interagency Review Panel (Regional Panel) changes in indicator status as well as additions and deletions to the 1988 National List were documented in Regional supplements. The National List was originally developed as an appendix to the Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al.1979) to aid in the consistent application of this classification system for wetlands in the field.. The 1996 National List also was developed to aid in determining the presence of hydrophytic vegetation in the Clean Water Act Section 404 wetland regulatory program and in the implementation of the swampbuster provisions of the Food Security Act. While not required by law or regulation, the Fish and Wildlife Service is making the 1996 National List available for review and comment.
    [Show full text]
  • Survival Types of High Mountain Plants Under Extreme Temperatures
    ARTICLE IN PRESS Flora 205 (2010) 3–18 Contents lists available at ScienceDirect Flora journal homepage: www.elsevier.de/flora Survival types of high mountain plants under extreme temperatures Walter Larcher Ã, Christine Kainmuller,¨ Johanna Wagner Institut fur¨ Botanik, Universitat¨ Innsbruck, Sternwartestrasse 15, A-6020 Innsbruck, Austria article info abstract Article history: Extreme temperatures are a main factor limiting plant growth in high mountain habitats. During winter, Received 20 September 2008 the risk of frost damage is highest at windblown and often snow-free sites. During summer, actively Accepted 2 December 2008 growing plants are particularly endangered by episodic cold spells, but also by short-term overheating. The current review gives an overview of extreme temperatures in the European Alps and observations of Keywords: temperature damage on plants in their natural habitats. Furthermore, seasonal time courses of frost and Bioclimate temperatures heat resistance derived from laboratory tests on different plant growth forms are presented. Study Frost resistance species were the cushion plants Silene acaulis, Minuartia sedoides, Saxifraga oppositifolia and Carex firma Heat resistance collected on wind-exposed ridges; the rosette plant Soldanella alpina collected on snow-protected sites, Cross-tolerance and three Sempervivum species collected in xerothermic habitats. Adaptation The temperature resistance of leaves, stems, rhizomes and roots were tested in two annual time Winter drought courses. Frost treatments were conducted in controlled freezers by rapid cooling (10 K hÀ1, for current resistance) as well as by stepwise cooling (1–3 K hÀ1, for hardening capacity). Heat treatments followed a standardised procedure by exposing samples to heat for 30 min in hot water baths.
    [Show full text]
  • Atlas of Rare Endemic Vascular Plants of the Arctic
    Atlas of Rare Endemic Vascular Plants of the Arctic Technical Report No. 3 About CAFF Theprogram for the Conservation of Arctic Flora and Fauna (CAFF) of the Arctic Council was established lo address the special needs of Arctic ecosystems, species and thcir habitats in the rapid ly developing Arctic region. Itwas initiated as one of'four programs of the Arctic Environmental Protcction Strategy (AEPS) which was adopted by Canada, Denmark/Greenland, Finland, lceland, Norway, Russia, Swcdcn and the United States through a Ministeria! Declaration at Rovaniemi, Finland in 1991. Other programs initi­ ated under the AEPS and overlaken hy the Are.tie Council are the ArcticMonitoring and assessment Programme (AMAP), the program for Emergency Prevention, Preparcd­ ness and Response (EPPR) and the program for Protection of the Arctic Marine Envi­ ronment (PAME). Sinceits inaugural mccti.ng in Ottawa, Canada in 1992, the CAFF program has provided scientists, conscrvation managers and groups, and indigenous people of the north with a distinct forum in which lo tackle a wide range of Arctic conservation issues at the cir­ cumpolar level. CAFF's main goals, which are achieved in keeping with the concepts of sustainable developrnertt and utilisation, are: • to conserve Arctic Jlora and fauna, thcir diversity and thcir habitats; • to protect the Arctic ecosystems from threats; • to improve conservation management laws, reg ulations and practices for the Arclic; • to integrale Arctic interests into global conservation fora. CAFF operates rhrough a system of Designated Agencies and National Representatives responsible for CAFF in thcir rcspcctivc countries. CAFF also has an International Work­ ing Group wh.ith has met annually to assess progrcss and to develop Annual WorkPlans.
    [Show full text]
  • Draft Plant Propagation Protocol
    Plant Propagation Protocol for Oxyria digyna ESRM 412 – Native Plant Production Protocol URL: https://courses.washington.edu/esrm412/protocols/OXDI3.pdf Images from google.com TAXONOMY Plant Family Scientific Name Polygonaceae Common Name Buckwheat Species Scientific Name Scientific Name Oxyria digyna Varieties Sub-species Cultivar Common Rheum digynum Synonym(s) Common Name(s) Wood Sorrel, Alpine Sorrel, Alpine Mountainsorrel, Mountain-sorrel, Oxyrie de Montagne Species Code (as OXDI3 per USDA Plants database) GENERAL INFORMATION Geographical range See above map12 Ecological Grows in a wide range of areas, particularly in rocky areas and scree distribution slopes, in alpine and subalpine areas.5,6,10 Does well in disturbed sites11 with soils not too acidic, and moist but well drained. Can grow successfully in open areas with little to no shade, and often grows beneath bird nests due to the high nitrogen content of the soil.4 Climate and elevation range Local habitat and Subalpine forest or wetland riparian species2 abundance Plant strategy type / Produces small, wind dispersed seeds, making it a weed-like pioneer successional stage species, especially in disturbed sites.3 Tolerant of sun stress, but not of interspecies competition, particularly that of Ranunculus glacialis. Is able to germinate after being buried beneath snow.8 Has an intermediate tolerance for shade, a low tolerance for drought and anoxic conditions, and is adapted to coarse to medium soils. Seedlings spread slowly and are moderately vigorous, and the plant does not usually propagate vegetatively.12 Plant characteristics Oxyria digyna is a perennial herb which grows to approx. 2ft tall and 1ft wide.4 It is hairless, having a branching crown and several stems11 with swollen nodes8, and it is reddish tinged11.
    [Show full text]
  • Alpine Flora
    ALPINE FLORA -- PLACER GULCH Scientific and common names mostly conform to those given by John Kartesz at bonap.net/TDC FERNS & FERN ALLIES CYSTOPTERIDACEAE -- Bladder Fern Family Cystopteris fragilis Brittle Bladder Fern delicate feathery fronds hiding next to rocks and cliffs PTERIDACEAE -- Maidenhair Fern Family Cryptogramma acrostichoides American Rockbrake two different types of fronds; talus & rocky areas GYMNOSPERMS PINACEAE -- Pine Family Picea englemannii Englemann's Spruce ANGIOSPERMS -- MONOCOTS CYPERACEAE -- Sedge Family Carex haydeniana Hayden's Sedge very common alpine sedge; compact, dark, almost triangular inflorescence Eriophorum chamissonis Chamisso's Cotton-Grass Cottony head; no leaves on culm ALLIACEAE -- Onion Family Allium geyeri Geyer's Onion pinkish; onion smell LILIACEAE -- Lily Family Llyodia serotina Alp Lily white; small plant in alpine turf MELANTHIACEAE -- False Hellebore Family Anticlea elegans False Deathcamas greenish white; showy raceme above basal grass-like leaves Veratrum californicum Cornhusk Lily; CA False Hellebore greenish; huge lvs; huge plant; mostly subalpine ORCHIDACEAE -- Orchid Family Plantanthera aquilonis Green Bog Orchid greenish, in bracteate spike, spur about as long as or a bit shorter than lip POACEAE -- Grass Family Deschampsia caespitosa Tufted Hair Grass open inflorescence; thin, wiry leaves; 2 florets/spikelet; glumes longer than low floret Festuca brachyphylla ssp. coloradoensis Short-leaf Fescue dark; narrow inflorescence; thin, wiry leaves Phleum alpinum Mountain Timothy dark;
    [Show full text]
  • (Dr. Sc. Nat.) Vorgelegt Der Mathematisch-Naturwissenschaftl
    Zurich Open Repository and Archive University of Zurich Main Library Strickhofstrasse 39 CH-8057 Zurich www.zora.uzh.ch Year: 2012 Flowers, sex, and diversity: Reproductive-ecological and macro-evolutionary aspects of floral variation in the Primrose family, Primulaceae de Vos, Jurriaan Michiel Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-88785 Dissertation Originally published at: de Vos, Jurriaan Michiel. Flowers, sex, and diversity: Reproductive-ecological and macro-evolutionary aspects of floral variation in the Primrose family, Primulaceae. 2012, University of Zurich, Facultyof Science. FLOWERS, SEX, AND DIVERSITY. REPRODUCTIVE-ECOLOGICAL AND MACRO-EVOLUTIONARY ASPECTS OF FLORAL VARIATION IN THE PRIMROSE FAMILY, PRIMULACEAE Dissertation zur Erlangung der naturwissenschaftlichen Doktorwürde (Dr. sc. nat.) vorgelegt der Mathematisch-naturwissenschaftliche Fakultät der Universität Zürich von Jurriaan Michiel de Vos aus den Niederlanden Promotionskomitee Prof. Dr. Elena Conti (Vorsitz) Prof. Dr. Antony B. Wilson Dr. Colin E. Hughes Zürich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s ist ein zentrales Ziel in der Evolutionsbiologie, die Muster der Vielfalt und die Prozesse, die sie erzeugen, zu verstehen.
    [Show full text]
  • Switzerland - Alpine Flowers of the Upper Engadine
    Switzerland - Alpine Flowers of the Upper Engadine Naturetrek Tour Report 8 - 15 July 2018 Androsace alpina Campanula cochlerariifolia The group at Piz Palu Papaver aurantiacum Report and Images by David Tattersfield Naturetrek Mingledown Barn Wolf's Lane Chawton Alton Hampshire GU34 3HJ UK T: +44 (0)1962 733051 E: [email protected] W: www.naturetrek.co.uk Tour Report Switzerland - Alpine Flowers of the Upper Engadine Tour participants: David Tattersfield (leader) with 16 Naturetrek clients Day 1 Sunday 8th July After assembling at Zurich airport, we caught the train to Zurich main station. Once on the intercity express, we settled down to a comfortable journey, through the Swiss countryside, towards the Alps. We passed Lake Zurich and the Walensee, meeting the Rhine as it flows into Liectenstein, and then changed to the UNESCO World Heritage Albula railway at Chur. Dramatic scenery and many loops, tunnels and bridges followed, as we made our way through the Alps. After passing through the long Preda tunnel, we entered a sunny Engadine and made a third change, at Samedan, for the short ride to Pontresina. We transferred to the hotel by minibus and met the remaining two members of our group, before enjoying a lovely evening meal. After a brief talk about the plans for the week, we retired to bed. Day 2 Monday 9th July After a 20-minute walk from the hotel, we caught the 9.06am train at Surovas. We had a scenic introduction to the geography of the region, as we travelled south along the length of Val Bernina, crossing the watershed beside Lago Bianco and alighting at Alp Grum.
    [Show full text]
  • Polygonaceae of Alberta
    AN ILLUSTRATED KEY TO THE POLYGONACEAE OF ALBERTA Compiled and writen by Lorna Allen & Linda Kershaw April 2019 © Linda J. Kershaw & Lorna Allen This key was compiled using informaton primarily from Moss (1983), Douglas et. al. (1999) and the Flora North America Associaton (2005). Taxonomy follows VAS- CAN (Brouillet, 2015). The main references are listed at the end of the key. Please let us know if there are ways in which the kay can be improved. The 2015 S-ranks of rare species (S1; S1S2; S2; S2S3; SU, according to ACIMS, 2015) are noted in superscript (S1;S2;SU) afer the species names. For more details go to the ACIMS web site. Similarly, exotc species are followed by a superscript X, XX if noxious and XXX if prohibited noxious (X; XX; XXX) according to the Alberta Weed Control Act (2016). POLYGONACEAE Buckwheat Family 1a Key to Genera 01a Dwarf annual plants 1-4(10) cm tall; leaves paired or nearly so; tepals 3(4); stamens (1)3(5) .............Koenigia islandica S2 01b Plants not as above; tepals 4-5; stamens 3-8 ..................................02 02a Plants large, exotic, perennial herbs spreading by creeping rootstocks; fowering stems erect, hollow, 0.5-2(3) m tall; fowers with both ♂ and ♀ parts ............................03 02b Plants smaller, native or exotic, perennial or annual herbs, with or without creeping rootstocks; fowering stems usually <1 m tall; fowers either ♂ or ♀ (unisexual) or with both ♂ and ♀ parts .......................04 3a 03a Flowering stems forming dense colonies and with distinct joints (like bamboo
    [Show full text]
  • Winter Frosts Reduce Flower Bud Survival in High-Mountain Plants
    plants Article Winter Frosts Reduce Flower Bud Survival in High-Mountain Plants Johanna Wagner *, Karla Gruber, Ursula Ladinig, Othmar Buchner and Gilbert Neuner * Department of Botany, Functional Plant Biology, University of Innsbruck, Sternwartestrasse 15, A-6020 Innsbruck, Austria; [email protected] (K.G.); [email protected] (U.L.); [email protected] (O.B.) * Correspondence: [email protected] (J.W.); [email protected] (G.N.); Tel.: +43-512-507-51026 (G.N.) Abstract: At higher elevations in the European Alps, plants may experience winter temperatures of −30 ◦C and lower at snow-free sites. Vegetative organs are usually sufficiently frost hardy to survive such low temperatures, but it is largely unknown if this also applies to generative structures. We investigated winter frost effects on flower buds in the cushion plants Saxifraga bryoides L. (subnival- nival) and Saxifraga moschata Wulfen (alpine-nival) growing at differently exposed sites, and the chionophilous cryptophyte Ranunculus glacialis L. (subnival-nival). Potted plants were subjected to short-time (ST) and long-time (LT) freezing between −10 and −30 ◦C in temperature-controlled freezers. Frost damage, ice nucleation and flowering frequency in summer were determined. Flower bud viability and flowering frequency decreased significantly with decreasing temperature and exposure time in both saxifrages. Already, −10 ◦C LT-freezing caused the first injuries. Below −20 ◦C, the mean losses were 47% (ST) and 75% (LT) in S. bryoides, and 19% (ST) and 38% (LT) in S. moschata. Winter buds of both saxifrages did not supercool, suggesting that damages were caused by freeze dehydration.
    [Show full text]
  • Specialist Report Charge
    Swan Lake Expansion Project (FERC Project No. 2911) Botany Resource Report FINAL Prepared for: Ketchikan-Misty Fiords Ranger District Tongass National Forest and Ketchikan, Alaska Prepared by: Kathryn Beck, Botanist Beck Botanical Services Karen Brimacombe, Ecologist McMillen, LLC January 2014 Botany Resource Report FINAL TABLE OF CONTENTS 1 Introduction .............................................................................................................................. 1 1.1 Project Description ........................................................................................................... 1 1.2 Regulatory Framework ..................................................................................................... 3 1.2.1 The National Forest Management Act of 1976 (NFMA) .................................... 3 1.2.2 USDA Departmental Regulations 9500-004 ....................................................... 3 1.2.3 36 Code of Federal Regulations (CFR) 219.19 (2000) ....................................... 3 1.2.4 Tongass Land and Resource Management Plan .................................................. 3 1.3 Analysis Area ................................................................................................................... 4 2 Action Alternatives and Reasonably Foreseeable Projects ...................................................... 4 2.1.1 No Action Alternative ......................................................................................... 5 2.1.2 Proposed Action Alternative ..............................................................................
    [Show full text]
  • Disentangling Drivers of Plant Endemism and Diversification
    Perspectives in Plant Ecology, Evolution and Systematics 28 (2017) 19–27 Contents lists available at ScienceDirect Perspectives in Plant Ecology, Evolution and Systematics journal homepage: www.elsevier.com/locate/ppees Disentangling drivers of plant endemism and diversification in the European MARK Alps – A phylogenetic and spatially explicit approach ⁎ Jan Smyčkaa, , Cristina Roqueta, Julien Renauda, Wilfried Thuillera, Niklaus E. Zimmermannb, Sébastien Lavergnea a Université Grenoble Alpes, CNRS, Laboratoire d’Ecologie Alpine (LECA), 2233 rue de la Piscine, FR-38000 Grenoble, France b Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland ARTICLE INFO ABSTRACT Keywords: Plant endemism in the European Alps is clustered into particular geographic areas. Two contrasted and non Glacial refugia exclusive hypotheses have been suggested to explain these hotspots of endemism: (i) those areas were glacial High elevation refugia, where endemism reflects survival-recolonisation dynamics since the onset of Pleistocene glaciations, (ii) Mountains those are high elevation mountain areas, where endemism was fostered by local speciation events due to geo- Speciation graphic isolation and harsh environmental niches, or by low dispersal ability of inhabiting species. Dispersal Here, we quantitatively compared these two hypotheses using data of species distribution in the European Phylogenetic uncertainty Alps (IntraBioDiv database), species phylogenetic relationships, and species ecological and biological char- acteristics. We developed a spatially and phylogenetically explicit modelling framework to analyze spatial patterns of endemism and the phylogenetic structure of species assemblages. Moreover, we analyzed inter- relations between species trait syndromes and endemism. We found that high endemism occurrs in potential glacial refugia, but only those on calcareous bedrock, and also in areas with high elevation.
    [Show full text]
  • How Does Genome Size Affect the Evolution of Pollen Tube Growth Rate, a Haploid Performance Trait?
    Manuscript bioRxiv preprint doi: https://doi.org/10.1101/462663; this version postedClick April here18, 2019. to The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv aaccess/download;Manuscript;PTGR.genome.evolution.15April20 license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Effects of genome size on pollen performance 2 3 4 5 How does genome size affect the evolution of pollen tube growth rate, a haploid 6 performance trait? 7 8 9 10 11 John B. Reese1,2 and Joseph H. Williams2 12 Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 13 37996, U.S.A. 14 15 16 17 1Author for correspondence: 18 John B. Reese 19 Tel: 865 974 9371 20 Email: [email protected] 21 1 bioRxiv preprint doi: https://doi.org/10.1101/462663; this version posted April 18, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 22 ABSTRACT 23 Premise of the Study – Male gametophytes of most seed plants deliver sperm to eggs via a 24 pollen tube. Pollen tube growth rates (PTGRs) of angiosperms are exceptionally rapid, a pattern 25 attributed to more effective haploid selection under stronger pollen competition. Paradoxically, 26 whole genome duplication (WGD) has been common in angiosperms but rare in gymnosperms.
    [Show full text]